Dental impression trays are used create a negative imprint of the teeth and surrounding tissue, which can then be used to make a cast or ‘positive’ model of the dentition. This cast may be used for the fabrication of dentures, crowns, removal dental devices, or other prostheses and orthodontics.
In order to create the most effective and accurate impression, the entire dental arch and supporting tissue should be included in the mold. However, in order to accommodate all mouth sizes, a plurality of different sized impression trays are required. Currently there are four standard sizes of dental impression trays. This process can become very inefficient when a user does not know which size impression tray is needed to accommodate his/her mouth. Historically, two separate styles of dental trays may be required, one for the upper arch and one for the lower arch. The lower tray is typically designed to accommodate tongue presence, while the upper tray is designed for palatal coverage. Therefore a need exists for a single adjustable dental impression tray which can comfortably accommodate a wide variety of either the upper or lower arch forms.
It is known in the art to have an adjustable dental impression tray with two halves connected by a front pivoting member as disclosed in Skinner (U.S. Pat. No. 7,270,540). Skinner teaches an impression tray comprised of two overlapping halves which are connected in the front by a pivoting member. However, as the two halves are opened, to accommodate a wider mouth, a large gap is created in the front of the impression tray where the impression material extrudes. Additionally, when separating the two dental impression halves by a pivoting member in the front, the natural arc of the dental tray rim is destroyed and will decrease effectiveness of the impression.
A disadvantage of existing non-adjustable trays is that they require multiple standard sizes. Additionally, an upper palate tray and a separate lower arch tray are needed to accommodate the arches. This results in waste of time while selecting the correct tray size, and a waste of storage space required to store the plurality of trays.
Further, another disadvantages of existing adjustable trays is that the arc created by the pivoting motion distorts the natural arc need to achieve an accurate impression. Additionally, as the two halves the dental tray are expanded, a large gap is created in the front rim of the tray and impression material extrudes out when pressure is applied.
Therefore, a need exists for a universal dental impression tray that can comfortably and accurately accommodate all mouth sizes. Moreover, a need exists for a dental tray which can be used for both the upper and/or lower arch.